The present invention relates generally to integrated power systems and methods for use in a variety of applications, such as in battery-powered vehicles, fuel cell vehicles, and hybrid electric vehicles. More specifically, the present invention relates to integrated power systems and methods including a traction inverter module and a bi-directional DC/DC converter combined into a single assembly.
Traditionally, the powertrain and power conversion systems of battery-powered vehicles, fuel cell vehicles, and hybrid electric vehicles (HEVs) (collectively referred to as xe2x80x9celectric vehiclesxe2x80x9d) have included a plurality of separate, discrete components and assemblies. Among these components and assemblies are the traction inverter module (TIM) and the bi-directional DC/DC converter (DC/DC converter). The TIM, also called the electric power inverter, converts the raw DC current generated by a battery or a fuel cell into an AC current capable of powering an electric motor, such as a field-oriented induction motor. This power is converted for driving and controlling the motor, i.e. for generating torque. The motor, in combination with a transaxle, converts the electrical energy into mechanical energy which turns the wheels of the electric vehicle. The DC/DC converter is the electric vehicle equivalent of the alternator of an internal combustion engine-powered vehicle. The DC/DC converter uses pulse-width modulation (PWM) to step the voltage associated with an electric vehicle""s high-voltage battery pack or fuel cell down to that which an alternator would usually generate (13.5 to 14V). The DC/DC converter is typically used to charge a 12V accessory/auxiliary battery, which is typically separated from the potentially dangerous high-voltage battery pack or fuel cell. The DC/DC converter may also be used to transfer power from the accessory/auxiliary battery to the high-voltage battery pack or fuel cell to, for example, start the electric vehicle.
Traditionally, the TIM and the DC/DC converter have been enclosed within separate, discrete castings, one in the front of the vehicle and one in the rear. The TIM and the DC/DC converter have utilized separate busbars to route incoming power to each, separate coldplates to cool the components of each, and separate connectors to connect each with other components and assemblies of the electric vehicle. This has increased the overall volume, weight, and complexity of the powertrain and power conversion systems. Thus, what is needed are integrated power systems and methods which combine the TIM and the DC/DC converter into a single assembly, reducing their overall volume, weight, and complexity.
The present invention provides integrated power systems and methods including a traction inverter module (TIM) and a bidirectional DC/DC converter (DC/DC converter).
In one embodiment, an integrated power system for use in an electric vehicle having a fuel cell and an electric motor includes a common casting, a traction inverter module operable for converting DC current generated by the fuel cell into AC current capable of powering the electric motor, and a DC/DC converter operable for stepping-down the voltage of the fuel cell. The traction inverter module and the DC/DC converter are disposed within the common casting.
In another embodiment, an electric vehicle having a fuel cell and an electric motor includes an integrated power system. The integrated power system includes a common casting, a traction inverter module operable for converting DC current generated by the fuel cell into AC current capable of powering the electric motor, and a DC/DC converter operable for stepping-down the voltage of the fuel cell. The traction inverter module and the DC/DC converter are disposed within the common casting.
In a further embodiment, an integrated power method for use in an electric vehicle having a fuel cell and an electric motor includes providing a common casting, providing a traction inverter module operable for converting DC current generated by the fuel cell into AC current capable of powering the electric motor, and providing a DC/DC converter operable for stepping-down the voltage of the fuel cell. The method also includes disposing the traction inverter module and the DC/DC converter within the common casting.
Advantageously, the integrated power systems and methods of the present invention combine the TIM and the DC/DC converter into a single assembly, reducing their overall volume, weight, and complexity.